June 11, 2009
Scoring the Dissociative Experiences Scale (DES)
I hope everyone has already recorded his or her score for the DES before reading this follow-up blog.
If you haven’t yet taken the DES, please do so before reading any further.
To explain the scoring of the DES, I’m going to quote some material from Dr. Colin Ross’s book “Dissociative Identity Disorder”. This information can also be found online at http://www.rossinst.com/dissociative_experiences_scale.html . Dr. Ross also provides a lengthy discussion about dissociation in the general population, charts, graphs, and comparative information with the DDIS, SCID-D, SCL-90, and MCMI.
The Dissociative Experiences Scale (DES) is a 28-item self-report instrument that can be completed in 10 minutes, and scored in less than 5 minutes. It is easy to understand, and the questions are framed in a normative way that does not stigmatize the respondent for positive responses. A typical DES question is, “Some people have the experience of finding new things among their belongings that they do not remember buying. Mark the line to show what percentage of the time this happens to you.” The respondent then slashes the line, which is anchored at 0% on the left and 100% on the right, to show how often he or she has this experience. The DES contains a variety of dissociative experiences, many of which are normal experiences.
The DES has very good validity and reliability, and good overall psychometric properties, as reviewed by its original developers (Carlson, 1994; Carlson & Armstrong, 1994; Carlson & Putnam, 1993; Carlson et al., 1993). It has excellent construct validity, which means it is internally consistent and hangs together well, as reflected in highly significant Spearman correlations of all items with the overall DES score. The scale is derived from extensive clinical experience with an understanding of DID. In the initial studies during its development and in all subsequent studies, the DES has discriminated DID from other diagnostic groups and controls at high levels of significance, based on either group mean or group median scores. In most samples, the mean and median DES scores for DID subjects are within 5 points of each other.
…The higher the DES score, the more likely it is that the person has DID. In a sample of 1,051 clinical subjects, however, only 17% of those scoring above 30 on the DES actually had DID (Carlson et al., 1993). The DES is not a diagnostic instrument. It is a screening instrument. High scores on the DES do not prove that a person has a dissociative disorder, they only suggest that clinical assessment for dissociation is warranted. This is how we report DES scores in our consults, as within or not within the range for DID, and as consistent or not consistent with the clinical and DDIS diagnosis of DID. DID subjects sometimes have low scores, so a low score does not rule out DID. In fact, given that in most studies the average DES score for a DID patient is in the 40s, and the standard deviation about 20, roughly about 15% of clinically diagnosed DID patients score below 20 on the DES…..
The DES is the only dissociative instrument that has been subjected to a number of replication studies by independent investigators. We found in our original replication (Ross, Norton, & Anderson, 1988) that it discriminated DID from other groups very well, with scores similar to those found by Bernstein and Putnam (1986), and this pattern has persisted in all subsequent research….
The DES can predict who will not, and who may have a dissociative disorder with high accuracy. As well, the DES taps into the dissociative component of general psychopathology… The DES is not just picking out a dissociative anomaly that is unconnected to anything else.
Because of the properties of the DES, and its extensive research base, It is the best self-report instrument for measuring dissociation available….
In other words, most trauma survivors that are clinically diagnosed with DID score in the 40’s on the DES, but survivors with DID can certainly score lower than 20 and higher than 69. Scores over 30 will indicate a high likelihood of the person having dissociative identity disorder.
Basically, the higher the score, the more likely the person has DID. The DES is not an official diagnostic tool, but it can certainly help to screen for people with dissociative disorders.
In my personal opinion, for dissociative people, the DES score will be somewhat dependent on who in the system takes the test. The parts that have more denial and dissociation from the rest of the system will likely score lower than others in the system that are more aware of the others inside. Also, I would guess that the DES score might vary with the different stages of therapy and treatment.
In any which way, the DES can be very helpful in your therapy process, and I strongly encourage you to discuss your scores in detail with your therapist. Various questions may have specific personal importance for you and can provide good foundational material for processing the ways your dissociation affects your life. The DES can give you an excellent starting place for talking about how life is for you as a dissociative person.
It can be helpful to take repeated DES tests over the course of your treatment, so you can record the changes over time. Hopefully, your dissociative scores will decrease as you progress through your therapy process.
- Which questions do you most relate to?
- If you have scored higher than 60% on any question, does your therapist understand that this experience is so common for you?
- Did you hear or sense internal arguing about how to answer any of the questions?
- Were you surprised to see any of the questions?
- Which questions asked you about dissociative experiences that you have not yet told other people that you experience?
- Do you find the DES to be upsetting? Comforting? Frightening? Confusing? …..? (fill in the blank)
Kathy Broady LCSW